A new number to contact police in London has been unveiled.

Members of the public can now dial '101' for non-emergency calls in response to figures which showed less than a quarter of '999' calls required an urgent response.

The new number is part of a national programme to improve access and will give the public one easy way to get in touch with the police for calls that do not require an urgent response.

For example, the public should call 101 to report a crime that has already happened, seek crime prevention advice or make us aware of local policing issues.

As with 999, calls to 101 in London will be handled 24 hours a day, seven days a week by specially trained officers and staff at the MPS's Central Communications Command who will help deal with enquiries.

According to official MPS figures, in April 2011 there were 161,008 recorded 999 calls, 32,941 (20%) of which were graded as an immediate response required i.e. a genuine emergency. This means the remaining 80% would be more appropriate for 101.

Metropolitan Police Service Assistant Commissioner for Territorial Policing, Ian McPherson, said: "The introduction of 101 is one of the biggest changes in the way people can contact the police since 999 was introduced in the 1940s.

"Having just two phone numbers - 101 for reporting a crime that has happened, to get advice or to raise local policing issues - or 999 if it's an emergency, makes calling the Met a lot easier and makes our services more accessible.

"It's also expected to reduce the number of inappropriate 999 calls the Met receives, enabling us to respond to genuine emergencies more effectively.

"Only about 20% of 999 calls require an emergency response from the police. 999 should only be used in an emergency, that is when a crime is happening, when someone suspected of a crime is nearby, or where someone is injured, being threatened or in danger.

"For all other matters the public should call us on 101.

"There are now many ways for the public to get in touch with the Met: you can approach an officer in the street; you can visit a police station or front counter 24/7; you can report crime or get advice on our website; you can join one of our virtual neighbourhood ward panels and now you can call 101 if you don't require an immediate response. We can also come to you at a time and place to suit you - last year we made 80,000 appointments. You can also get in touch with your local (Safer Neighbourhoods) policing team to discuss policing or crime concerns in your area.

"Even if your first language is not English we can still help as we can set up a three-way conversation between the caller, police operator and a qualified interpreter. We also have a text phone service for people who are deaf or hard of hearing.

"Dialling 101 provides a direct link to your police, where you can get information, advice and access to your local policing teams.

"101 is just one of the ways we are improving and modernising our services - a commitment demonstrated by increased levels of public confidence in the MPS - now one of the highest levels of all UK police forces. The MPS is here for London and we are determined to keep on improving our services while making them accessible to all communities in London."

Mayor of London Boris Johnson welcomed the introduction of 101.

He said: "This quick and easy 101 number will help with a wide breadth of important issues that don't require an immediate response. Some people have inadvertently used '999' for things which aren't emergencies, and this number will free up our blue light brigade to concentrate on critical matters, whilst offering the public an excellent way of reporting other issues.

"We've been exploring the widespread potential for this service at City Hall and I hope this number will be more widely adopted in the future across an even broader range of services."

Supporting today's launch Home Office minister for policing Nick Herbert said: "This is a significant step forward in our ambition to reconnect the police and public. 101 in London will give the public a memorable non-emergency number so that they can get in touch with local forces.

"It will make crime easier to report and help the police to tackle crime and disorder."

Commander Ian Dyson, City of London Police and ACPO lead on contact management, said: "101 is a number to ring your local police force. It's simple and straight forward. If it's an emergency call 999 if it's not, call 101. This number provides a universal, easy to remember 3-digit telephone number for people living or working in London.

"We would remind the public that they should always continue to call 999 in an emergency - for example, when an immediate response is needed because a crime is happening, someone suspected of a crime is nearby, or someone is injured, being threatened or in danger."